A semiconductor light emitting device is a semiconductor device which emits light of various colors by the recombination of electrons and holes in a p-n junction between a p-type semiconductor and an n-type semiconductor when a current is applied thereto. When compared with a filament-based light emitting device, a semiconductor light emitting device has a longer lifespan, lower power consumption, superior initial driving characteristic, higher vibration resistance, and so on. Hence, the demand for semiconductor light emitting device is continuously increasing. Specifically, a great deal of attention has recently been paid to a group III nitride semiconductor which can emit light in a short-wavelength region, such as a series of blue colors.
A nitride single-crystal, which constitutes a light emitting device using a group III nitride semiconductor, is formed over a substrate for specific single-crystal growth, e.g., a sapphire substrate or a SiC substrate. However, there are considerable limitations on the arrangement of electrodes when an insulation substrate, such as a sapphire substrate, is used. Specifically, in the case of a conventional nitride semiconductor light emitting device, electrodes are generally arranged in a horizontal direction, which causes a narrow current flow. Such a narrow current flow increases an operating voltage (Vf) of the nitride semiconductor light emitting device, which degrades current efficiency. In addition, the nitride semiconductor light emitting device is vulnerable to electrostatic discharge. To solve these problems, there is a need for a nitride semiconductor light emitting device having an optimized chip structure and electrode structure.